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UPPER NAUGARH SMALL HYDROELECTRIC PROJECT (8MW)

UPPER NAUGARH SMALL HYDROELECTRIC PROJECT (8MW)

Upper Naugarh Gad Small Hydroelectric Project is a Run-Off-River type project which is developed by Api Power Company Limited. The project is located at 5km upstream of Naugarh Gad Hydroelectric Project (8.5MW) Intake which had been succefully constructed and operated by the same Company. The Project is located in Dhuligada and Shikhar VDC's of Darchula district in the Far Western Development Region of Nepal. Geographically, the site is located between Latitude 29044'18''N to 29043'25''N and Longitude 80039'48''E to 80036'26''E. The Headworks and the Powerhouse are located at an elevation of 1040.20m and 877.0m from mean sea level. The Project has installed capacity of 8MW with 163.44m of gross head and 6.43 m3/s at 40% of exceedence. The Project is accessible from Gokuleshwor to Headworks area as there is existing acess road. The powerhouse consists of two units of 4000 kW Francis turbines connected to two units of 4150 kVA generators which generate the electricity. The power is evacuated through 33 kV transmission line (9 km) which is connected to the Balanch Substation of Chameliya Hydroelectric Project, NEA. 

The company has obtained survey license of the Project for 8 MW on dated 7th Jestha, 2071 from the Department of Electricity Development, Ministry of Energy and completed the Detailed Survey of the Project. Company has entered into the Power Purchase Agreement with Nepal Electricity Authority on dated 12th Kartik, 2073 B.S. The IEE has already been approved by the Ministry of Energy and the Land acquisition for the Project has been completed. Company has obtained the Generation Licence from Ministry of Energy, Department of Electricity Development (DOED) on dated 14th Poush, 2073 B.S.

The Project has started its Commercial Operation from 13th Kartik, 2076 B.S. (30th October, 2019). 

 

Project Description

Project Details
Project Name : Upper Naugarh Gad Hydroelectric Project
Development Region : Far Western
Zone : Mahakali
District : Darchula
Intake Site : Shikhar VDC
Powerhouse Site : Dhuligada VDC
Geographical Co-ordinates
Latitude : 29°44'18" N to 29°43'25" N
Longitude : 80°39'48" E to 80°36'26" E
General
Water Source : Naugarh Gad and Gadi Gad (Mauli Khola)
Nearest Town : Gokuleshwor
Type of Scheme : Run-of-river
Gross Head : 163.44 m
Net Head : 144.0 m
Installed Capacity : 8,000 kW
Hydrology
Catchment Area : 171.8 km2
Average Annual Precipitation : 2192 mm/year
100 years Design Flood (HW) : 498 m3/s
100 years Design Flood (PH) : 563 m3/s
Minimum Monthly Flow : 2.71 m3/s
Riparian Release Intake
Naugarh Gad : 0.233 m3/s
Mauli Collection : 0.38m3/sec
Headworks
Diversion Structure : Hard Stone Lined Gravity Free Flow Weir
Type of Weir : Concrete gravity dam
Length of Weir : 22 m
Weir Crest Elevation : EL 1040.20 msl
Height of Weir : 2.50 m from U/s Apron
Undersluice : 1 Vertical Sluice Gates
Crest of Sluice : EL 1037.70 msl
Size of Sluice Gate (b x h) : 2.50 m x 2.00 m
Intake Type : Side Intake
Size of Opening : 2.20 x 0.90 – 3 nos
Crest Elevation of Intake : EL 1039.20 msl
Gravel Trap
Type : Rectangular
No. of bays : 1
Particle Size to be Settled : 50 mm
Trap Efficiency : 98 %
Size of Gravel Trap (LxBxH) : 15.00 m x 5.00  x (1.75 m – 3.25 m)
Spilway Length : 14.80 m
Bed Slope : 1:10
Flushing Channel Size : 1 Nos. of 1.0 m x 1.0 m Rectangular Closed
Desander
Type : Double Dufour Double Chamber Continuos Flushing Type
Trap Efficiency : 90%
Size of Each Chamber (LxBxH) : 55.0 m x 6.80 m x (4.45m – 6.50m)
Bed Slope : 1:50
FSL @ Desander end : 1040.00 msl
Flushing Channel Size : 2 Nos. of 0.80 m x 0.80 m Rectangular
Headworks at Mauli Khola
Diversion Structure : Hard Stone Lined Gravity Free Flow Weir
Length of Weir : 13.30 m
Weir Crest Elevation : EL 1045.00 msl
Height of Weir : 1.0 m from U/S Apron
Undersluice : 1 Vertical Sluice Gate
Crest of Sluice : EL 1043.50 msl
Size of Sluice Gate (b x h) : 2.00 m x 1.50 m
Intake Type : Side Intake with orifice opening
Size of Intake : 4.80 x 0.50 - 1
Crest Elevation of Intake : EL 1044.55 msl
Approach Canal
Type : Closed Rectangular Canal
Length : 65 m
Size (b x h) : 1.20 m x 1.20 m
Bed Slope : 1:250
Desander
Type : Flat Bed Continuous Flushing
Chamber : 2 Nos
Particle Size to be settled : 0.20 mm
Trap Efficiency : 90%
Size of Each Chamber(l x b x h) : 36 m x 3.70 m x (1.70 m - 3.50 m)
Bed Slope : 1:50
FSL at Desander end : 1044.59 msl
Flushing Channel Size : 2 Nos of 0.50 m x 0.50 m Rectangular
Headrace Pipe  
Type : MS-Pipe beried Section
Total Length : 5149.85 m
Pipe Material : IS 2062-B
Thickness : 8 mm to 16 mm
Diameter of Pipe : 1.70 - 1.65 m ID
Mauli Collection Pipe
Total Length : 1236.173 m
Type : MS-Pipe Buried Section
Pipe Material : IS 2062-B
Thickness : 6 mm - 8 mm
Diameter of Pipe : 0.80 - 0.7 m
Surge Tank
Type : Surface, RCC Rectangular
Number of Chamber : 2 (Lower and Upper)
Size
Lower Tank (L x B x H) : 22.5 m x 8.00 m x 8.00 m
Upper Tank (L x B x H) : 22.5 m x 8.00 m x 8.00 m
Steady State Level : 1023.10 masl
Upper Surge Level : 1047.70 masl
Down Surge Level : 1019.12 masl
Invert Level
Lower Surge Tank : 1015.40 masl
Upper Surge Tank : 1040.00 masl
Penstock Pipe
Type : MS-Pipe Open Structure
Length : 181.5 m from T to Surgetank and 233.00m from T to Powerhouse
Pipe Materialize : IS 2062-B
Size of Pipe :1.65~1.17m 16 to 20mm thick(T-ST) &1.50m, 14 to 8mm thick(T-PH)
Powerhouse
Type : Surface
PH Dimensions, main Building (l x b) : 30.50 m x 16.00 m
Height of PH Building : 11.50 from Plinth Level
PH Floor Level : EL 878.50 m
Tailrace
Type : Closed Rectangular RCC Canal
Length : 70 m
Size (w x h) : 2.5 m x 2.80 m
Tailrace Water Level : 876.76 m
Slope : 1:500
Turbine
Type of Turbine : Francis
Number : Two (2)
Shaft Arrangement : Horizontal
Rated Discharge for each Turbine : 2.7 m3/s
Rated head : 145.43 m
Rated Output for each Unit : 3650 kW
RPM : 1000
Rated Efficiency : 90 % (at 100% Discharge)
Generator
Type : Synchronous brushless, 3Ø AC
No of Units : 2
Rated Voltage : 6.3 kVA
Power Factor : 0.85
Layout : Horizontal
Rated Efficiency : 96%
Rated Output : 4150 kVA
Rated Frequency : 50 Hz.
Power Transformer
Type : Step up Power Transformer
Rated Capacity : 10000 kVA
Rated Efficiency : 99%
No of Unit : 1
Number of Phases : 3 ph, 50 Hz
Types of Connection : Star/Delta
Type of Cooling : ONAN
Voltage Ratio : 6.3 kV (LV Side) / 33 kV (HV Side)
Station Supply Transformer
Type : Indoor and Outdoor Type
Rate Power Output : 200 kVA
No of Unit : 2
Type of Cooling : ONAN
Voltage Ratio : 6.3/0.4 kV
Connection / Vector Group : Dyn11
Transmission & Interconnection
Power House – Balanch Substation : 7 km
Type of Circuit : 33 kV Single Circuit Line up to 132 kV Balanch S/S
Line Conductor : ACSR "DOG"
Transmission Voltage : 33 kV
Proposed Interconnection Point : Balanch 33/132 kV Substation
Power and Energy
Installed Capacity : 8.00 MW
Total Gross Energy : 51.69 GWh
Contract Energy after Outage & Loss : 49.10 GWh
Wet Saleable Energy : 39.40 GWh (79.27%)
Dry Saleable Energy : 12.29 GWh (20.73%)
Project Financial Indicators
Base Cost of the Project : 1272.404 Millions NRs(Without IDC)
Cost After Financing : 1738
Loan/ Equity Ratio : 70:30
Interest Rate : 11 %
Internal Rate of Return : 16.72%
Simple Payback Period : 5.15 years
B/C Ratio : 1.51
Return of Equity : 26.17%
Cost per MW : 17.38 Crores/MW after Financing